OpenRaiser/Intern-Atlas huggingface dataset:
Dpraodv: A Dyanamic Learning System Against Blackhole Attack in Aodv Based Manet
Venue: arXiv cs.CR 2009
Year: 2009

Security is an essential requirement in mobile ad hoc networks to provide protected communication between mobile nodes. Due to unique characteristics of MANETS, it creates a number of consequential challenges to its security design. To overcome the challenges, there is a need to build a multifence security solution that achieves both broad protection and desirable network performance. MANETs are vulnerable to various attacks, blackhole, is one of the possible attacks. Black hole is a type of routing attack where a malicious node advertise itself as having the shortest path to all nodes in the environment by sending fake route reply. By doing this, the malicious node can deprive the traffic from the source node. It can be used as a denial-of-service attack where it can drop the packets later. In this paper, we proposed a DPRAODV (Detection, Prevention and Reactive AODV) to prevent security threats of blackhole by notifying other nodes in the network of the incident. The simulation results in ns2 (ver- 2.33) demonstrate that our protocol not only prevents blackhole attack but consequently improves the overall performance of (normal) AODV in presence of black hole attack.
Performing Hybrid Recommendation in Intermodal Transportation-the FTMarket System's Recommendation Module
Venue: arXiv cs.AI 2009
Year: 2009

Diverse recommendation techniques have been already proposed and encapsulated into several e-business applications, aiming to perform a more accurate evaluation of the existing information and accordingly augment the assistance provided to the users involved. This paper reports on the development and integration of a recommendation module in an agent-based transportation transactions management system. The module is built according to a novel hybrid recommendation technique, which combines the advantages of collaborative filtering and knowledge-based approaches. The proposed technique and supporting module assist customers in considering in detail alternative transportation transactions that satisfy their requests, as well as in evaluating completed transactions. The related services are invoked through a software agent that constructs the appropriate knowledge rules and performs a synthesis of the recommendation policy.
Excel Modelling - Transparency, Auditing and Business Use
Venue: arXiv cs.SE 2009
Year: 2009

Within Lloyds Banking Group the heritage HBOS Corporate division deals with Corporate loans, and is required to assess these loans for risk in accordance with the Basle Accord regulations. Statistical Risk Rating models are developed by the risk analysts to assess the obligors credit worthiness. It is necessary then to provide the bankers who originated the loan ('Relationship Managers' or RMs) with an assessment tool to generate the loan rating upon which they base their lending decisions. Heritage HBoS Corporate required a new model build system for holding its Risk Rating models in 2006 as a result of more complex models being created to comply with the Basle Accord. The use of Excel was promoted by the IT department for a number of reasons; the Excel solution now in use is reviewed in this paper.
Marking-up multiple views of a Text: Discourse and Reference
Venue: arXiv cs.CL 2009
Year: 2009

We describe an encoding scheme for discourse structure and reference, based on the TEI Guidelines and the recommendations of the Corpus Encoding Specification (CES). A central feature of the scheme is a CES-based data architecture enabling the encoding of and access to multiple views of a marked-up document. We describe a tool architecture that supports the encoding scheme, and then show how we have used the encoding scheme and the tools to perform a discourse analytic task in support of a model of global discourse cohesion called Veins Theory (Cristea & Ide, 1998).
A Common XML-based Framework for Syntactic Annotations
Venue: arXiv cs.CL 2009
Year: 2009

It is widely recognized that the proliferation of annotation schemes runs counter to the need to re-use language resources, and that standards for linguistic annotation are becoming increasingly mandatory. To answer this need, we have developed a framework comprised of an abstract model for a variety of different annotation types (e.g., morpho-syntactic tagging, syntactic annotation, co-reference annotation, etc.), which can be instantiated in different ways depending on the annotator's approach and goals. In this paper we provide an overview of the framework, demonstrate its applicability to syntactic annotation, and show how it can contribute to comparative evaluation of parser output and diverse syntactic annotation schemes.
Language Models for Handwritten Short Message Services
Venue: arXiv cs.CL 2009
Year: 2009

Handwriting is an alternative method for entering texts composing Short Message Services. However, a whole new language features the texts which are produced. They include for instance abbreviations and other consonantal writing which sprung up for time saving and fashion. We have collected and processed a significant number of such handwriting SMS, and used various strategies to tackle this challenging area of handwriting recognition. We proposed to study more specifically three different phenomena: consonant skeleton, rebus, and phonetic writing. For each of them, we compare the rough results produced by a standard recognition system with those obtained when using a specific language model.
Blind user detection in doubly-dispersive DS/CDMA channels
Venue: arXiv cs.IT 2009
Year: 2009

In this work, we consider the problem of detecting the presence of a new user in a direct-sequence/code-division-multiple-access (DS/CDMA) system with a doubly-dispersive fading channel, and we propose a novel blind detection strategy which only requires knowledge of the spreading code of the user to be detected, but no prior information as to the time-varying channel impulse response and the structure of the multiaccess interference. The proposed detector has a bounded constant false alarm rate (CFAR) under the design assumptions, while providing satisfactory detection performance even in the presence of strong cochannel interference and high user mobility.
Decomposition of the NVALUE constraint
Venue: arXiv cs.AI 2009
Year: 2009

We study decompositions of NVALUE, a global constraint that can be used to model a wide range of problems where values need to be counted. Whilst decomposition typically hinders propagation, we identify one decomposition that maintains a global view as enforcing bound consistency on the decomposition achieves bound consistency on the original global NVALUE constraint. Such decompositions offer the prospect for advanced solving techniques like nogood learning and impact based branching heuristics. They may also help SAT and IP solvers take advantage of the propagation of global constraints.
Comparing Single and Multiobjective Evolutionary Approaches to the Inventory and Transportation Problem
Venue: arXiv cs.NE 2009
Year: 2009

EVITA, standing for Evolutionary Inventory and Transportation Algorithm, is a two-level methodology designed to address the Inventory and Transportation Problem (ITP) in retail chains. The top level uses an evolutionary algorithm to obtain delivery patterns for each shop on a weekly basis so as to minimise the inventory costs, while the bottom level solves the Vehicle Routing Problem (VRP) for every day in order to obtain the minimum transport costs associated to a particular set of patterns. The aim of this paper is to investigate whether a multiobjective approach to this problem can yield any advantage over the previously used single objective approach. The analysis performed allows us to conclude that this is not the case and that the single objective approach is in gene- ral preferable for the ITP in the case studied. A further conclusion is that it is useful to employ a classical algorithm such as Clarke & Wright's as the seed for other metaheuristics like local search or tabu search in order to provide good results for the Vehicle Routing Problem.
A possible low-level explanation of "temporal dynamics of brightness induction and White's illusion"
Venue: arXiv cs.CV 2009
Year: 2009

Based upon physiological observation on time dependent orientation selectivity in the cells of macaque's primary visual cortex together with the psychophysical studies on the tuning of orientation detectors in human vision we suggest that time dependence in brightness perception can be accommodated through the time evolution of cortical contribution to the orientation tuning of the ODoG filter responses. A set of Difference of Gaussians functions has been used to mimic the time dependence of orientation tuning. The tuning of orientation preference and its inversion at a later time have been considered in explaining qualitatively the temporal dynamics of brightness perception observed in "Brief presentations reveal the temporal dynamics of brightness induction and White's illusion" for 58 and 82 ms of stimulus exposure.
Improving Effectiveness Of ELearning In Maintenance Using Interactive 3D
Venue: arXiv cs.CY 2009
Year: 2009

In aerospace and defense, training is being carried out on the web by viewing PowerPoint presentations, manuals and videos that are limited in their ability to convey information to the technician. Interactive training in the form of 3D is a more cost effective approach compared to creation of physical simulations and mockups. This paper demonstrates how training using interactive 3D simulations in elearning achieves a reduction in the time spent in training and improves the efficiency of a trainee performing the installation or removal.
Dealing with incomplete agents' preferences and an uncertain agenda in group decision making via sequential majority voting
Venue: arXiv cs.AI 2009
Year: 2009

We consider multi-agent systems where agents' preferences are aggregated via sequential majority voting: each decision is taken by performing a sequence of pairwise comparisons where each comparison is a weighted majority vote among the agents. Incompleteness in the agents' preferences is common in many real-life settings due to privacy issues or an ongoing elicitation process. In addition, there may be uncertainty about how the preferences are aggregated. For example, the agenda (a tree whose leaves are labelled with the decisions being compared) may not yet be known or fixed. We therefore study how to determine collectively optimal decisions (also called winners) when preferences may be incomplete, and when the agenda may be uncertain. We show that it is computationally easy to determine if a candidate decision always wins, or may win, whatever the agenda. On the other hand, it is computationally hard to know wheth er a candidate decision wins in at least one agenda for at least one completion of the agents' preferences. These results hold even if the agenda must be balanced so that each candidate decision faces the same number of majority votes. Such results are useful for reasoning about preference elicitation. They help understand the complexity of tasks such as determining if a decision can be taken collectively, as well as knowing if the winner can be manipulated by appropriately ordering the agenda.
Flow-Based Propagators for the SEQUENCE and Related Global Constraints
Venue: arXiv cs.AI 2009
Year: 2009

We propose new filtering algorithms for the SEQUENCE constraint and some extensions of the SEQUENCE constraint based on network flows. We enforce domain consistency on the SEQUENCE constraint in $O(n^2)$ time down a branch of the search tree. This improves upon the best existing domain consistency algorithm by a factor of $O(\log n)$. The flows used in these algorithms are derived from a linear program. Some of them differ from the flows used to propagate global constraints like GCC since the domains of the variables are encoded as costs on the edges rather than capacities. Such flows are efficient for maintaining bounds consistency over large domains and may be useful for other global constraints.
Envy, Multi Envy, and Revenue Maximization
Venue: arXiv cs.GT 2009
Year: 2009

We study the envy free pricing problem faced by a seller who wishes to maximize revenue by setting prices for bundles of items. If there is an unlimited supply of items and agents are single minded then we show that finding the revenue maximizing envy free allocation/pricing can be solved in polynomial time by reducing it to an instance of weighted independent set on a perfect graph. We define an allocation/pricing as \textit{multi envy free} if no agent wishes to replace her allocation with the union of the allocations of some set of other agents and her price with the sum of their prices. We show that it is \textit{coNP}-hard to decide if a given allocation/pricing is multi envy free. We also show that revenue maximization multi envy free allocation/pricing is \textit{APX} hard. Furthermore, we give efficient algorithms and hardness results for various variants of the highway problem.
Cross-correlation properties of cyclotomic sequences
Venue: arXiv cs.IT 2009
Year: 2009

Sequences with good correlation properties are widely used in engineering applications, especially in the area of communications. Among the known sequences, cyclotomic families have the optimal autocorrelation property. In this paper, we decide the cross-correlation function of the known cyclotomic sequences completely. Moreover, to get our results, the relations between the multiplier group and the decimations of the characteristic sequence are also established for an arbitrary difference set.
On graphs without a C4 or a diamond
Venue: arXiv cs.DM 2009
Year: 2009

We consider the class of (C4, diamond)-free graphs; graphs in this class do not contain a C4 or a diamond as an induced subgraph. We provide an efficient recognition algorithm for this class. We count the number of maximal cliques in a (C4, diamond)-free graph and the number of n-vertex, labeled (C4, diamond)-free graphs. We also give an efficient algorithm for finding a largest clique in the more general class of (house, diamond)-free graphs.
Characteristics of multithreading models for high-performance IO driven network applications
Venue: arXiv cs.NI 2009
Year: 2009

In a technological landscape that is quickly moving toward dense multi-CPU and multi-core computer systems, where using multithreading is an increasingly popular application design decision, it is important to choose a proper model for distributing tasks across multiple threads that will result in the best efficiency for the application and the system as a whole. The work described in this paper creates, implements and evaluates various models of distributing tasks to CPU threads and investigates their characteristics for use in modern high-performance network servers. The results presented here comprise a roadmap of models for building multithreaded server applications for modern server hardware and Unix-like operating systems.
Regular Matroids with Graphic Cocircuits
Venue: arXiv cs.DM 2009
Year: 2009

We introduce the notion of graphic cocircuits and show that a large class of regular matroids with graphic cocircuits belongs to the class of signed-graphic matroids. Moreover, we provide an algorithm which determines whether a cographic matroid with graphic cocircuits is signed-graphic or not.
Expressing advanced user preferences in component installation
Venue: arXiv cs.SE 2009
Year: 2009

State of the art component-based software collections - such as FOSS distributions - are made of up to dozens of thousands components, with complex inter-dependencies and conflicts. Given a particular installation of such a system, each request to alter the set of installed components has potentially (too) many satisfying answers. We present an architecture that allows to express advanced user preferences about package selection in FOSS distributions. The architecture is composed by a distribution-independent format for describing available and installed packages called CUDF (Common Upgradeability Description Format), and a foundational language called MooML to specify optimization criteria. We present the syntax and semantics of CUDF and MooML, and discuss the partial evaluation mechanism of MooML which allows to gain efficiency in package dependency solvers.
Expected RIP: Conditioning of The Modulated Wideband Converter
Venue: arXiv cs.IT 2009
Year: 2009

The sensing matrix of a compressive system impacts the stability of the associated sparse recovery problem. In this paper, we study the sensing matrix of the modulated wideband converter, a recently proposed system for sub-Nyquist sampling of analog sparse signals. Attempting to quantify the conditioning of the converter sensing matrix with existing approaches leads to unreasonable rate requirements, due to the relatively small size of this matrix. We propose a new conditioning criterion, named the expected restricted isometry property, and derive theoretical guarantees for the converter to satisfy this property. We then show that applying these conditions to popular binary sequences, such as maximal codes or Gold codes, leads to practical rate requirements.
Formal Verification of Full-Wave Rectifier: A Case Study
Venue: arXiv cs.LO 2009
Year: 2009

We present a case study of formal verification of full-wave rectifier for analog and mixed signal designs. We have used the Checkmate tool from CMU [1], which is a public domain formal verification tool for hybrid systems. Due to the restriction imposed by Checkmate it necessitates to make the changes in the Checkmate implementation to implement the complex and non-linear system. Full-wave rectifier has been implemented by using the Checkmate custom blocks and the Simulink blocks from MATLAB from Math works. After establishing the required changes in the Checkmate implementation we are able to efficiently verify the safety properties of the full-wave rectifier.
Fast Algorithm for Finding Unicast Capacity of Linear Deterministic Wireless Relay Networks
Venue: arXiv cs.IT 2009
Year: 2009

The deterministic channel model for wireless relay networks proposed by Avestimehr, Diggavi and Tse `07 has captured the broadcast and inference nature of wireless communications and has been widely used in approximating the capacity of wireless relay networks. The authors generalized the max-flow min-cut theorem to the linear deterministic wireless relay networks and characterized the unicast capacity of such deterministic network as the minimum rank of all the binary adjacency matrices describing source-destination cuts whose number grows exponentially with the size of the network. In this paper, we developed a fast algorithm for finding the unicast capacity of a linear deterministic wireless relay network by finding the maximum number of linearly independent paths using the idea of path augmentation. We developed a modified depth-first search algorithm tailored for the linear deterministic relay networks for finding linearly independent paths whose total number proved to equal the unicast capacity of the underlying network. The result of our algorithm suggests a capacity-achieving transmission strategy with one-bit length linear encoding at the relay nodes in the concerned linear deterministic wireless relay network. The correctness of our algorithm for universal cases is given by our proof in the paper. Moreover, our algorithm has a computational complexity bounded by $O(|{\cal{V}}_x|\cdot C^4+d\cdot |{\cal{V}}_x|\cdot C^3)$ which shows a significant improvement over the previous results for solving the same problem by Amaudruz and Fragouli (whose complexity is bounded by $O(M\cdot |{\cal{E}}|\cdot C^5)$ with $M\geq d$ and $|{\cal{E}}|\geq|{\cal{V}}_x|$) and by Yazdi and Savari (whose complexity is bounded by $O(L^8\cdot M^{12}\cdot h_0^3+L\cdot M^6\cdot C\cdot h_0^4)$ with $h_0\geq C$).
Differential Privacy via Wavelet Transforms
Venue: arXiv cs.DB 2009
Year: 2009

Privacy preserving data publishing has attracted considerable research interest in recent years. Among the existing solutions, {\em $ε$-differential privacy} provides one of the strongest privacy guarantees. Existing data publishing methods that achieve $ε$-differential privacy, however, offer little data utility. In particular, if the output dataset is used to answer count queries, the noise in the query answers can be proportional to the number of tuples in the data, which renders the results useless. In this paper, we develop a data publishing technique that ensures $ε$-differential privacy while providing accurate answers for {\em range-count queries}, i.e., count queries where the predicate on each attribute is a range. The core of our solution is a framework that applies {\em wavelet transforms} on the data before adding noise to it. We present instantiations of the proposed framework for both ordinal and nominal data, and we provide a theoretical analysis on their privacy and utility guarantees. In an extensive experimental study on both real and synthetic data, we show the effectiveness and efficiency of our solution.
Acceptable Complexity Measures of Theorems
Venue: arXiv cs.LO 2009
Year: 2009

In 1931, Gödel presented in Königsberg his famous Incompleteness Theorem, stating that some true mathematical statements are unprovable. Yet, this result gives us no idea about those independent (that is, true and unprovable) statements, about their frequency, the reason they are unprovable, and so on. Calude and Jürgensen proved in 2005 Chaitin's "heuristic principle" for an appropriate measure: the theorems of a finitely-specified theory cannot be significantly more complex than the theory itself. In this work, we investigate the existence of other measures, different from the original one, which satisfy this "heuristic principle". At this end, we introduce the definition of acceptable complexity measure of theorems.
Improved Hardness of Approximation for Stackelberg Shortest-Path Pricing
Venue: arXiv cs.DS 2009
Year: 2009

We consider the Stackelberg shortest-path pricing problem, which is defined as follows. Given a graph G with fixed-cost and pricable edges and two distinct vertices s and t, we may assign prices to the pricable edges. Based on the predefined fixed costs and our prices, a customer purchases a cheapest s-t-path in G and we receive payment equal to the sum of prices of pricable edges belonging to the path. Our goal is to find prices maximizing the payment received from the customer. While Stackelberg shortest-path pricing was known to be APX-hard before, we provide the first explicit approximation threshold and prove hardness of approximation within 2-o(1).
Analysis, Design and Simulation of a New System for Internet Multimedia Transmission Guarantee
Venue: arXiv cs.MM 2009
Year: 2009

QoS is a very important issue for multimedia communication systems. In this paper, a new system that reinstalls the relation between the QoS elements (RSVP, routing protocol, sender, and receiver) during the multimedia transmission is proposed, then an alternative path is created in case of original multimedia path failure. The suggested system considers the resulting problems that may be faced within and after the creation of rerouting path. Finally, the proposed system is simulated using OPNET 11.5 simulation package. Simulation results show that our proposed system outperforms the old one in terms of QoS parameters like packet loss and delay jitter.
Web-enabling Cache Daemon for Complex Data
Venue: arXiv cs.DC 2009
Year: 2009

One of the most common basic techniques for improving the performance of web applications is caching frequently accessed data in fast data stores, colloquially known as cache daemons. In this paper we present a cache daemon suitable for storing complex data while maintaining fine-grained control over data storage, retrieval and expiry. Data manipulation in this cache daemon is performed via standard SQL statements so we call it SQLcached. It is a practical, usable solution already implemented in several large web sites.